Northeast Journal of Complex Systems最新文献

{"title":"An Implementation of The Method of Moments on Chemical Systems with Constant and Time-dependent Rates","authors":"Emmanuel Adara, R. B. Sidje","doi":"10.22191/nejcs/vol5/iss1/8/","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/8/","url":null,"abstract":"Among numerical techniques used to facilitate the analysis of biochemical reactions, we can use the method of moments to directly approximate statistics such as the mean numbers of molecules. The method is computationally viable in time and memory, compared to solving the chemical master equation (CME) which is notoriously expensive. In this study, we apply the method of moments to a chemical system with a constant rate representing a vascular endothelial growth factor (VEGF) model, as well as another system with time-dependent propensities representing the susceptible, infected, and recovered (SIR) model with periodic contact rate. We assess the accuracy of the method using comparisons with approximations obtained by the stochastic simulation algorithm (SSA) and the chemical Langevin equation (CLE). The VEGF model is of interest because of the role of VEGF in the growth of cancer and other inflammatory diseases and the potential use of anti-VEGF therapies in the treatment of cancer. The SIR model is a popular epidemiological model used in studying the spread of various infectious diseases in a population.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115695754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Politicians, Pundits, and Platform Migration: A Comparison of Political Polarization on Parler and Twitter","authors":"Abigial Matthews, Jacqueline M. Otala, Esma Wali, Gillian Kurtic, Lynden Millington, Michael Simpson, Jeanna Neefe Matthews, Golshan Madraki","doi":"10.22191/nejcs/vol1/iss1/5/","DOIUrl":"https://doi.org/10.22191/nejcs/vol1/iss1/5/","url":null,"abstract":"Parler, a self-proclaimed free speech social media platform founded in 2018, attracted a large influx of new members in 2020 as the result of a highly visible platform migration campaign. Parler usage was linked to the planning of the Jan. 6, 2021 attack on the United States Capitol building, leading to a shutdown of the Parler platform. Parler, which is now back online, offers an important lens through which to examine the broader attempts at platform migration in response to changing content moderation and platform governance policies and their impact on political polarization. We begin by examining the network connections between US Congressional Representatives on both Twitter and Parler. We find that Parler has a homogenous population of users, consisting of a single isolated group, where polarization seems irrelevant, while Twitter demonstrates two clearly polarized groups. We compare how politicians and political pundits use Parler differently. Finally, we examine the evolution of Parler including comparing Parler’s own policies before and after the shutdown and reflecting on the future of platforms like Parler and similar platform migration experiments.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114334826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"She is an Expert in this Research Field: The Signal of Recent Publications' Relevance","authors":"G. Zeevi, O. Mokryn","doi":"10.22191/nejcs/vol5/iss1/7","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/7","url":null,"abstract":"Assessing the expertise of researchers has garnered increased interest recently. This heightened focus arises from the growing emphasis on interdisciplinary science and the subsequent need to form expert teams. When forming these teams, the coordinators need to assess expertise in fields that are often very different from theirs. The conventional reliance on signals of success, prestige, and academic impact can unintentionally perpetuate biases within the assessment process. This traditional approach favors senior researchers and those affiliated with prestigious institutions, potentially overlooking talented individuals from underrepresented backgrounds or institutions. This paper addresses the challenge of determining expertise by proposing a methodology that leverages the relevance of a researcher's recent publication track to the proposed research as a \"sensemaking\" signal. We introduce a novel {em $alpha-$relevance} metric between the trained embedding over the titles and abstracts of a researcher's recent publications and the embedding of a call and show that high values of {em $alpha-$relevance} indicate expertise in the field of the call. By evaluating the {em $alpha-$relevance} threshold, we establish a robust framework for the assessment process. For the evaluation process, we use (1) NIH grant-winning records and researchers' publications obtained from Scopus and (2) grant submissions dataset from a research university and the corresponding researchers' publications. Additionally, we investigate the optimal time window required to capture the researcher's expertise based on their publication timeline. Considering the temporal relationship between grant winnings and publications, we identify the most informative time window reflecting the researcher's relevant contributions. The data-driven methodology transcends traditional signals of success, promoting a fair evaluation process of the researcher's relevance to the proposed research. By leveraging objective indicators, we aim to facilitate the formation of expert teams across disciplines while mitigating biases in assessing expertise.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"748 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122964303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"She is an Expert in this Research Field: The Signal of Recent Publications' Relevance","authors":"Gil Zeevi, Osnat Mokryn","doi":"10.22191/nejcs/vol5/iss1/7/","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/7/","url":null,"abstract":"Assessing the expertise of researchers has garnered increased interest recently. This heightened focus arises from the growing emphasis on interdisciplinary science and the subsequent need to form expert teams. When forming these teams, the coordinators need to assess expertise in fields that are often very different from theirs. The conventional reliance on signals of success, prestige, and academic impact can unintentionally perpetuate biases within the assessment process. This traditional approach favors senior researchers and those affiliated with prestigious institutions, potentially overlooking talented individuals from underrepresented backgrounds or institutions. This paper addresses the challenge of determining expertise by proposing a methodology that leverages the relevance of a researcher's recent publication track to the proposed research as a \"sensemaking\" signal. We introduce a novel {em $alpha-$relevance} metric between the trained embedding over the titles and abstracts of a researcher's recent publications and the embedding of a call and show that high values of {em $alpha-$relevance} indicate expertise in the field of the call. By evaluating the {em $alpha-$relevance} threshold, we establish a robust framework for the assessment process. For the evaluation process, we use (1) NIH grant-winning records and researchers' publications obtained from Scopus and (2) grant submissions dataset from a research university and the corresponding researchers' publications. Additionally, we investigate the optimal time window required to capture the researcher's expertise based on their publication timeline. Considering the temporal relationship between grant winnings and publications, we identify the most informative time window reflecting the researcher's relevant contributions. The data-driven methodology transcends traditional signals of success, promoting a fair evaluation process of the researcher's relevance to the proposed research. By leveraging objective indicators, we aim to facilitate the formation of expert teams across disciplines while mitigating biases in assessing expertise.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135568847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incorporating Complexity Theory in Collaborative Educational Programs","authors":"Ximeng Chen","doi":"10.22191/nejcs/vol5/iss1/6/","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/6/","url":null,"abstract":"The field of education has witnessed an increasing trend of inter-organizational and inter-departmental collaborations and forming of networks. Collaborative educational programs have been implemented in a variety of ways. This paper proposes to understand and study collaborative educational programs through the lens of complexity theory and to utilize nonlinear research methods. This paper also proposes to connect the dots in the literature among complexity theory, collaborative educational programs, program evaluation, and alternative nonlinear research methods.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":" 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114088267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Politicians, Pundits, and Platform Migration: A Comparison of Political Polarization on Parler and Twitter","authors":"Abigial Matthews, Jacqueline M. Otala, Esma Wali, Gillian Kurtic, Lynden Millington, Michael Simpson, Jeanna Matthews, Golshan Madraki","doi":"10.22191/nejcs/vol5/iss1/5/","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/5/","url":null,"abstract":"Parler, a self-proclaimed free speech social media platform founded in 2018, attracted a large influx of new members in 2020 as the result of a highly visible platform migration campaign. Parler usage was linked to the planning of the Jan. 6, 2021 attack on the United States Capitol building, leading to a shutdown of the Parler platform. Parler, which is now back online, offers an important lens through which to examine the broader attempts at platform migration in response to changing content moderation and platform governance policies and their impact on political polarization. We begin by examining the network connections between US Congressional Representatives on both Twitter and Parler. We find that Parler has a homogenous population of users, consisting of a single isolated group, where polarization seems irrelevant, while Twitter demonstrates two clearly polarized groups. We compare how politicians and political pundits use Parler differently. Finally, we examine the evolution of Parler including comparing Parler’s own policies before and after the shutdown and reflecting on the future of platforms like Parler and similar platform migration experiments.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134950793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathogen Emergence As Complex Biological Invasion: Lessons From Dynamical Systems Modeling","authors":"Sudam Surasinghe, Marisabel Rodriguez-Messan, Victor Meszaros, Jane Molofksy, S. Almagro-Moreno, Brandon Ogbunugafor","doi":"10.22191/nejcs/vol5/iss1/4/","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/4/","url":null,"abstract":"Infectious disease emergence has become the target of cross-disciplinary efforts that aim to understand and predict the shape of outbreaks. The many challenges involved with the prediction of disease emergence events is a characteristic that in- fectious diseases share with biological invasions in many subfields of ecology (e.g., how certain plants are able to successfully invade a new niche). Like infectious diseases, biological invasions by plants and animals involve interactions between agents (pathogens and plants in their respective cases) and a recipient niche. In this study, we examine the problem of pathogen emergence through the lens of a framework first developed for the study of plant invasions, restructured to apply to pathogen invaders. We utilize mathematical techniques to examine how com- plex dynamics emerge between the various actors in a multi-component pathogen invasion process, which implies invasion frameworks can offer new insight on the particulars of infectious disease emergence. Summarizing, we consider these re- sults in context of their application to epidemiology, and more broadly with regards to modern efforts to bring the vernacular of complex systems to more real-world systems and problems. In doing so, we demonstrate the potential power in math- ematizing conceptual models, and connecting ideas across disparate fields, toward a more rigorous picture of the nuances that underlie the dynamics of biological systems","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128404333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extending the Spectral Difference Method with Divergence Cleaning (SDDC) to the Hall MHD Equations","authors":"Russ Hankey, Kuangxu Chen, C. Liang","doi":"10.22191/nejcs/vol5/iss1/1","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/1","url":null,"abstract":"The Hall Magnetohydrodynamic (MHD) equations are an extension of the standard MHD equations that include the “Hall” term from the general Ohm’s law. The Hall term decouples ion and electron motion physically on the ion inertial length scales. Implementing the Hall MHD equations in a numerical solver allows more physical simulations for plasma dynamics on length scales less than the ion inertial scale length but greater than the electron inertial length. The present effort is an important step towards producing physically correct results to important problems, such as the Geospace Environmental Modeling (GEM) Magnetic Reconnection problem. The solver that is being modified is currently capable of solving the resistive MHD equations on unstructured grids using the spectral difference scheme which is an arbitrarily high-order method that is relatively simple to parallelize. The GEM Magnetic Reconnection problem is used to evaluate whether the Hall MHD equations have been correctly implemented in the solver using the spectral difference method with divergence cleaning (SDDC) algorithm by comparing against the reconnection rates reported in the literature.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132336229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporality-induced chaos in the Kuramoto Model","authors":"Keanu Mason Rock, Hamza Dirie, S. P. Cornelius","doi":"10.22191/nejcs/vol5/iss1/3","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/3","url":null,"abstract":"Switched dynamical systems have been extensively studied in engineering literature in the context of system control. In these systems, the dynamical laws change between different subsystems depending on the environment, a process that is known to produce emergent behaviors---notably chaos. These dynamics are analogous to those of temporal networks, in which the network topology changes over time, thereby altering the dynamics on the network. It stands to reason that temporal networks may therefore produce emergent chaos and other exotic behaviors unanticipated in static networks, yet concrete examples remain elusive. Here, we present a minimal example of a networked system in which temporality produces chaotic dynamics not possible in any static subnetwork alone. Specifically, we consider a variant of the famous Kuramoto model, in which the network topology alternates between different configurations in response to the phase dynamics. We show under certain conditions this can produce a strange attractor, and we verify the presence of chaos by analyzing its geometrical properties. Our results provide new insights on the consequences of temporality for network dynamics, and acts as a proof of concept for a novel mechanism behind generating chaotic dynamics in networks.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134077896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing Controversiality of Topics Utilizing Eccentricity of Opinions","authors":"Sriniwas Pandey, Hiroki Sayama","doi":"10.22191/nejcs/vol5/iss1/2","DOIUrl":"https://doi.org/10.22191/nejcs/vol5/iss1/2","url":null,"abstract":"Access to abundant biased information in echo chambers and social bubbles often intensifies opinions to the extremes. The extremization of opinions results in several topics becoming controversial. However, it is very difficult to measure the degree of controversiality of a topic objectively since the controversiality of any topic is subjective and perceived differently from different communities. The absence of an objective measure of controversiality has been a major hindrance in understanding the causes and effects of it. In this work we propose a method to quantify controversiality of a topic by utilizing eccentricity of opinions on that topic. The eccentricity of an opinion is the amount of strangeness of the opinion relative to other opinions in the social neighborhood. The collective eccentricity of all opinions for a topic works as an indicator of the controversiality of that topic and can be represented by any measure of central tendency. With the help of social network data, we also demonstrate that opinions on several issues related to our routine life show similar trends for diversity though they differ in their controversiality.","PeriodicalId":184569,"journal":{"name":"Northeast Journal of Complex Systems","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122353544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}